Implement the CRTC/Plane disable functionality of drm_framebuffer_remove
using the atomic API, and use it if possible.
For atomic drivers, this removes the possibility of several commits when
a framebuffer is in use by more than one CRTC/plane.
Additionally, this will provide a suitable place to support the removal
of a framebuffer from a writeback connector, in the case that a
writeback connector is still actively using a framebuffer when it is
removed by userspace.
Signed-off-by: Brian Starkey <brian.starkey@xxxxxxx>
---
drivers/gpu/drm/drm_framebuffer.c | 154 ++++++++++++++++++++++++++++++++++++-
1 file changed, 152 insertions(+), 2 deletions(-)
diff --git a/drivers/gpu/drm/drm_framebuffer.c b/drivers/gpu/drm/drm_framebuffer.c
index 528f75d..b02cf73 100644
--- a/drivers/gpu/drm/drm_framebuffer.c
+++ b/drivers/gpu/drm/drm_framebuffer.c
@@ -22,6 +22,7 @@
#include <linux/export.h>
#include <drm/drmP.h>
+#include <drm/drm_atomic.h>
#include <drm/drm_auth.h>
#include <drm/drm_framebuffer.h>
@@ -795,6 +796,148 @@ void drm_framebuffer_cleanup(struct drm_framebuffer *fb)
EXPORT_SYMBOL(drm_framebuffer_cleanup);
/**
+ * __drm_framebuffer_remove_atomic - atomic version of __drm_framebuffer_remove
+ * @dev: drm device
+ * @fb: framebuffer to remove
+ *
+ * If the driver implements the atomic API, we can handle the disabling of all
+ * CRTCs/planes which use a framebuffer which is going away in a single atomic
+ * commit.
+ *
+ * This scans all CRTCs and planes in @dev's mode_config. If they're using @fb,
+ * it is removed and the CRTC/plane disabled.
+ * The legacy references are dropped and the ->fb pointers set to NULL
+ * accordingly.
+ *
+ * Returns:
+ * true if the framebuffer was successfully removed from use
+ */
+static bool __drm_framebuffer_remove_atomic(struct drm_device *dev,
+ struct drm_framebuffer *fb)
+{
+ struct drm_modeset_acquire_ctx ctx;
+ struct drm_atomic_state *state;
+ struct drm_connector_state *conn_state;
+ struct drm_connector *connector;
+ struct drm_plane *plane;
+ struct drm_crtc *crtc;
+ unsigned plane_mask;
+ int i, ret;
+
+ drm_modeset_acquire_init(&ctx, 0);
+
+ state = drm_atomic_state_alloc(dev);
+ if (!state)
+ return false;
+
+ state->acquire_ctx = &ctx;
+
+retry:
+ drm_for_each_crtc(crtc, dev) {
+ struct drm_plane_state *primary_state;
+ struct drm_crtc_state *crtc_state;
+
+ primary_state = drm_atomic_get_plane_state(state, crtc->primary);
+ if (IS_ERR(primary_state)) {
+ ret = PTR_ERR(primary_state);
+ goto fail;
+ }
+
+ if (primary_state->fb != fb)
+ continue;
+
+ crtc_state = drm_atomic_get_crtc_state(state, crtc);
+ if (IS_ERR(crtc_state)) {
+ ret = PTR_ERR(crtc_state);
+ goto fail;
+ }
+
+ /* Only handle the CRTC itself here, handle the plane later */
+ ret = drm_atomic_set_mode_for_crtc(crtc_state, NULL);
+ if (ret != 0)
+ goto fail;
+
+ crtc_state->active = false;
+
+ /* Get the connectors in order to disable them */
+ ret = drm_atomic_add_affected_connectors(state, crtc);
+ if (ret)
+ goto fail;
+ }
+
+ plane_mask = 0;
+ drm_for_each_plane(plane, dev) {
+ struct drm_plane_state *plane_state;
+
+ plane_state = drm_atomic_get_plane_state(state, plane);
+ if (IS_ERR(plane_state)) {
+ ret = PTR_ERR(plane_state);
+ goto fail;
+ }
+
+ if (plane_state->fb != fb)
+ continue;
+
+ plane->old_fb = plane->fb;
+ plane_mask |= 1 << drm_plane_index(plane);
+
+ /*
+ * Open-coded copy of __drm_atomic_helper_disable_plane to avoid
+ * a dependency on atomic-helper
+ */
+ ret = drm_atomic_set_crtc_for_plane(plane_state, NULL);
+ if (ret != 0)
+ goto fail;
+
+ drm_atomic_set_fb_for_plane(plane_state, NULL);
+ plane_state->crtc_x = 0;
+ plane_state->crtc_y = 0;
+ plane_state->crtc_w = 0;
+ plane_state->crtc_h = 0;
+ plane_state->src_x = 0;
+ plane_state->src_y = 0;
+ plane_state->src_w = 0;
+ plane_state->src_h = 0;
+ }
+
+ /* All of the connectors in state need disabling */
+ for_each_connector_in_state(state, connector, conn_state, i) {
+ ret = drm_atomic_set_crtc_for_connector(conn_state,
+ NULL);
+ if (ret)
+ goto fail;
+ }
+
+ if (WARN_ON(!plane_mask)) {
+ DRM_ERROR("Couldn't find any usage of [FB:%d]\n", fb->base.id);
+ ret = -ENOENT;
+ goto fail;
+ }
+
+ ret = drm_atomic_commit(state);
+
+fail:
+ drm_atomic_clean_old_fb(dev, plane_mask, ret);
+
+ if (ret == -EDEADLK)
+ goto backoff;
+
+ if (ret != 0)
+ drm_atomic_state_free(state);
+
+ drm_modeset_drop_locks(&ctx);
+ drm_modeset_acquire_fini(&ctx);
+
+ return ret ? false : true;
+
+backoff:
+ drm_atomic_state_clear(state);
+ drm_modeset_backoff(&ctx);
+
+ goto retry;
+}
+
+/**
* __drm_framebuffer_remove - remove all usage of a framebuffer object
* @dev: drm device
* @fb: framebuffer to remove
@@ -869,9 +1012,16 @@ void drm_framebuffer_remove(struct drm_framebuffer *fb)
* in-use fb with fb-id == 0. Userspace is allowed to shoot its own foot
* in this manner.
*/
- if (drm_framebuffer_read_refcount(fb) > 1)
- if (!__drm_framebuffer_remove(dev, fb))
+ if (drm_framebuffer_read_refcount(fb) > 1) {
+ bool removed;
+ if (dev->mode_config.funcs->atomic_commit)
+ removed = __drm_framebuffer_remove_atomic(dev, fb);
+ else
+ removed = __drm_framebuffer_remove(dev, fb);
+
+ if (!removed)
DRM_ERROR("failed to remove fb from active usage\n");
+ }
drm_framebuffer_unreference(fb);
}
--
1.7.9.5
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